The primary aims of Core A: Biostatistics, Epidemiology and Administrative are to maintain a high level of statistical competency, uniform standards of measurements and high quality of data for the research projects and to administer the overall program project. Core A will perform data management for the projects. A relational database is used to manage the data and increase the efficiency and accuracy of data flow. This core will also be responsible for the measurements of bone mass, anthropometrics, dietary intake, and physical activity for Projects 1 and 2. Existing quality assurance programs for these measurements will be continued while new programs will be developed and implemented for new measurements, such as peripheral quantitative tomography for the rats in Project 3. In addition, this core will perform statistical analysis on the comparison of strains of rats in Project 3, and on epidemiologic questions arising from data collected in Projects 1 and 2. Core A ill be responsible for the financial and overall administration of the entire program project.